Connection Failed: Rejected by host

Nope, it's a current issue with ICO. It basically means the game either disbanded or started, but hasn't been refreshed off the available games list. So there's no actual game to join even though the list shows there is.

It'll be fixed soon

-For now be sure to refresh the game list before you try to join
-Also, once in a while there is a host problem...see below:

• Other players aren't able to connect to the game I'm hosting.

Your user.setting file has an entry for GameHostPort (default is 6112). Make sure your router has this Port Forwarded to your computer's IP address or has UPnP enabled.

XP
C:\Documents and Settings\user\Local Settings\Application Data\Ironclad Games\Sins of a Solar Empire\Setting

Vista
C:\Users\yourname\AppData\Local\Ironclad Games\Sins of a Solar Empire\Setting

All computers behind a router should have their own unique GameHostPort setup in case the original host leaves and a new host for the game is needed.  Be sure to restart your game after changing these settings.

Example (computers behind router):

Computer IP          user.settings -> GameHostPort       Router Port Forwarding Setting

192.168.1.47                         6001                             6001   ->  192.168.1.47
192.168.1.201                       6002                             6002   ->   192.168.1.201
192.168.1.35                         6003                             6003   ->   192.168.1.35

• Q: Where can I get more help with setting up my computer for multiplayer?

A: We recommend you check out:

http://www.kiclan.com/Monk/Networking_for_the_Gamer_by_the_Monk.pdf

Another site we recommend is: http://portforward.com/default.htm
https://forums.sinsofasolarempire.com/?forumid=410&aid=174432

Ok no problems, i have no problem to host games though! but thankx for the info !

Great game i havnt even beaten the Computer yet lmoa (Must be a bug :P)